What was found
WHILE WORKING WRI 31-30/9464, TECH FOUND A SHORTED WIRE HARNESS IN AVIONICS COMPT. THE 3 PHASE WIRE HARNESS FROM THE EXTERNAL POWER RELAY HAS MADE CONTACT WITH GND BUS STRIP T268 (LOCATED DIRECTLY ABOVE APU GCU). INITIAL VISUAL INSPECTION SHOWS SEVERAL GND STUDS ARE BURNED/DAMAGED, ONE OR MORE WIRES FROM EPR ARE DAMAGED AND A SECOND HARNESS LOCATED IN THE SAME AREA APPEARS TO BE DAMAGED. INSTALLED T00268 PER WDM 91-21-41 PG 37, EXT POWER FEEDER CABLES PER WDM 91-21-11 PG 1, UP LIST 91-21-11 PG1 AND AS PER MM 20-20-00, BOEING SWPM CHAPT 20. REF EA 7-2440-119592 USE OF ORIGINAL TERMINAL STRIP IN REVERSE POSITION.